What is email segmentation?

The theory behind segmentation is that if you can identify groups of subscribers within your mailing list based on certain criteria and then tailor messages that will specifically appeal to those subscribers, then they will be more likely to respond favorably to those messages, boosting your engagement and conversion rates. It’s basically an advanced way of personalizing emails to individuals within segments that you define within your mailing list.

Sounds pretty logical and you’d think that virtually all email marketers would be segmenting their butts off at every opportunity to get optimal results for their email campaigns, but as it turns out, segmentation is still a fairly underused practice. These days, most decent ESP platforms make it pretty easy to define segments and deploy messages to specific groups within a mailing list, so the “advanced” part isn’t in the technical process.

The biggest challenge to email segmentation is in collecting the data from subscribers that makes it possible to classify them into segments in the first place and then knowing when and how to use this data effectively to maximize subscriber engagement.

It’s this challenge that still poses a barrier to email segmentation for many email marketers despite being well aware of its benefits.

Subscriber segments

So how do you collect data for the purpose of segmentation?

The obvious place to collect data is during signup. This opportunity is lost for marketers who offer an “email address only” signup, but marketers who provide an email signup form that requests a few more details about the subscribers usually have a good base to work from at least on a basic level.

As a rule, it’s recommended to keep the number of details requested during signup to a bare minimum and include only what’s absolutely necessary for marketers to perform the segmentation that’s crucial to their business, because long and exhaustive forms usually turn people off from subscribing at all.

You can always request more details later on once you’ve had a chance to establish trust with your subscribers and demonstrate that your content is valuable. You can do this either by encouraging subscribers to update their email preferences for your email program (having made sure that your “email preference page” includes the details you require for the purpose of segmentation) or by sending emails specifically requesting these details from your subscribers (via a dedicated form), clearly explaining how the provision of these details will enable you to send them content or offers that are better targeted to their personal preferences and interests.

The more data you accumulate about your subscribers over time, the more efficiently you will be able to identify the various subscriber persona that make sense to segment messages for.

Examples of newsletter signup forms that request minimal but essential details

Examples of newsletter signup forms that request minimal details to allow for basic but essential segmentation.

Using Progressive Profiling to segment your mailing list

Even when you don’t have a lot of data about your subscribers, you can still segment them into groups based on their interaction with your emails over time (hence “progressive” profiling). For example, you can easily tell your frequent openers from those who rarely open your emails, and same goes for clicks. If you dig deeper, you can also establish which subscribers consistently click on certain types of links in your emails. This allows you to create reasonably accurate segments of subscribers based on subjects or offers that interest them, or on their level of activity (so that they can be rewarded) or inactivity (so that they can be re-engaged).

According to a recent report from Experian Marketing Services, 70% of brands did not personalize emails sent to subscribers in 2013 but most marketers (83%) segmented their email campaign audiences by past activity data. This demonstrates that despite the challenges of segmentation, progressive profiling seems to be one segmentation method that email marketers do feel comfortable with, most likely because it doesn’t rely on information provided by the subscribers themselves.

What type of data should you collect for the purpose of segmentation?

The data that makes sense for one company to segment by may not necessarily be relevant for another, so deciding what criteria is important for segmentation purposes should really be based on your specific business requirements and email program’s goals. The types of data suggested below are relatively mainstream, but if your business caters for a niche audience, then obviously you should request details that are relevant for your segmentation purposes. If you own a pet store, for example, it would make sense for you to ascertain what type of pet your subscriber owns so that you’re not bombarding him with dog-food promotions when he in fact owns goldfish.

First Name

Who are you?

Being able to refer to a subscriber by his first name isn’t really a form of segmentation, but it is about as basic as you can get with personalization in email, so for those email marketers who see segmentation as “the deep end of the pool” but feel like they’re still wading around with inflatable armbands, the “first name” detail is a gentle way to inch further towards the deep end.

From the subscriber’s point of view, it’s nicer to be greeted with “Hi %first name%” than “Dear Valued Customer” because it feel as though the sender is talking to him as an individual and not to just another anonymous subscriber on a mailing list.



Any retailer that sells products that are relevant to either men or women must be able to distinguish between his female and male email subscribers. Knowing the subscriber’s sex is precisely the thing that can prevent an email featuring a promotion on high-heel shoes from ever reaching a businessman who would prefer a promotion for neckties and vice versa.

That’s not to say that some women may not be interested in certain items on behalf of the men in their lives or that men won’t on occasion be on the lookout for something for the women in their lives, but knowing how to package these items properly for the right audience (like this nice example from ModCloth) is key to getting the desirable reaction and not an “unsubscribe” as a result of repeatedly irrelevant offers.



Sometimes your products or news is applicable to everyone no matter where they are in the world, but in some situations you might have promotions or information that is only relevant to subscribers in specific countries.

Knowing which country your subscribers are from can help sharpen your messaging so that you’re not sending certain people content that’s irrelevant to them. It also helps you review the performance of your emails based on the geographical location of your subscribers. For example, if you can see from ongoing analysis that your French subscribers are particularly engaged with your emails (even if you hadn’t intended it), you might decide to tailor a promotion specifically for your French audience in order to maximize sales.



If your catalogue includes many types of products or services, then knowing exactly what interests each subscriber can help you customize emails with messaging that will be particularly relevant to them. For example, let’s say you offer tips or products relating to cooking, gardening, arts & crafts, pet care, parenting, health and fitness, mobile games and car maintenance (there are gazillions of potential categories obviously). If you can find out which of these areas are of particular interest to each subscriber, you can then customize each email so that it contains only (or mainly) the content that appeals to its recipient.

The more your subscribers feel that your content is relevant to them, the higher the likelihood that they will engage with your emails.


Birthday candles

There are three main reasons why knowing your subscribers birthday is helpful:

1) Sending Birthday Emails helps to endear your brand to a subscriber by making him feel warm and fuzzy that you “remembered” this special day and rewarded him for his loyalty by offering either a birthday greeting, or better yet – some sort of birthday gift.

2) Knowing the age of your subscribers can help you classify them into age brackets that can sometimes also help you target certain messages for maximum relevance. You could even use different language to appeal to different age brackets. For example, you might have something to offer that’s particularly relevant for college students but not really for anyone else, or for people of retirement age and no one else (etc).

3) In some cases, marketers must verify that subscribers are over a certain age in order to send them emails.

Purchase History


This one’s also a no-brainer if you have easy access to this data. Pioneered famously by Amazon and now widely used by many other online retail giants (although not always effectively), the idea is to send people relevant content based on their recent purchases.

The problem with this approach is that in some cases the content sent as a result of a purchase isn’t always relevant. For example, a friend of mine once bought a watch through one of the big online shopping portals, and for the next few months kept receiving emails from this portal trying to interest him in more watches. Something was obviously flawed in the automation process here, because it should have been taken into consideration that once someone buys something, why would he want to buy the same thing (or something very similar) again so soon? Needless to say that my friend unsubscribed, and so would anyone else once their tolerance level was breached.

The smart way to segment based on purchase history is to consider the type of items that were purchased and then send targeted offers (in a timely and respectful frequency) about complementary items. For example, if someone just purchased an airline ticket for a vacation or business trip, there’s no need to sell him another vacation or business trip so soon after this purchase, but it would make sense to send an email with hotel recommendations or local attractions. Or if someone just bought a new bed, you could send them an email offering bed linen options. Or, if someone just download a whitepaper on email marketing, you could send them an email recommending other whitepapers that may be of interest.

There’s never a “hotter” time to strike a shopper with an additional relevant offer than at checkout time or just after the purchase, but only as long as the offer makes sense, otherwise it’s just plain pushy and annoying.

TO SUM UP: Segmentation isn’t always necessary for every email you send, but if you identify situations where tailoring messages for certain subscribers would boost their relevance significantly and you have access to data that allowed you to create the necessary segments in your mailing list, then it would be a missed opportunity not to do so.

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